Bur-grinding machine



Feb. 27, 11923.

J. NORTHROP ET AL BUR GRINDING MACHINE 4 sheets-sheet l WWW Feb. 27, 11923.

J. NORTHIROP' ET AL BUR GRINDING MACHINE Filed June 24, 1 919 4 sheets-sheet 2 IM VW' Feb. 27, 1192?. 11,446,654-

- J. NOR'E'HROP ET AL BUR GRINDING MACHINE Filed June 2 1919 4 sheets-sheet 5 IF eb. 27, 11923. 11,446,654

J. NORTHROP ET AL BUR GRINDING MACHINE Filed June 24, 1919 4 shee'ts-sheefu '4 Patented Feb. 27, 1923.

narrate stares earenr @FFHCE.

JONAS NORTHROP, 01F HOPEDALE, AND GEORGE E. KILBURN, PETER P. PESSOTTI,

AND ERNEST L. TUCKER, OF MILFORD, MASSACHUSETTS, ASSIGNORS T0 HOPE- DALE MANUFACTURING COMPANY, OF MILFURD, MASSACHUSETTS, A CORPORA- TION .OF MASSACHUSETTS.

BUR-GRINDING MACHINE.

Application filed June 24, 1919.

To all whom it may concern Be it known that we, JONAS NORTHROP, a citizen of the United States, residing at Hopedale, in the county of Worcester, Commonwealth of Massachusetts, and whose post-office address Gnonon E. KILBURN, PETER P. Pnsso'r'rr, and Ennfns'r L. TUCKER, citizens of the United States, residing at Milford, in the county of Worcester, Commonwealth of Massachusetts. and whose post-oiiice addresses are all lt lilford. Mass, have invented certain new and useful Improvements in Bur-Grinding Machines; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which-it appertains to make and use the same.

This invention relates to grinding machines. and more particularly to bur grinding machines for use in removing the burs on stamped sheet metal articles.

Whenarticles, such as drop looms, are stamped out of sheet metal blanks, the rawedges resulting from the stamping operation form burs which are at present removed by hand grindingonthe ordinary rotary grinding wheels. In such cases, especially when it is desired to produce the metal articles-inquantity, it is necessary to maintain a large and expensive operating force in order to keep up a quantity production which obviously increases the cost of man ufacture f the article.

The object of the invention isto provide an automatic grinding machine, in which metal articles may be ground quickly and in a very inexpensive and advantageous manner.

The specific object of the invention is to provide an automatic machine in which drop wires may be formed, and ground.

To the accomplishment of these objects and such other objects as may appear, the invention consists in the structure hereinafter described and particularly defined in the claims," g

In theif-dra'wings which illustrate the preferred embodiment of the invention Fig. 1 is a side elevation of the bur grinding ma chine showing a sufficient portion of the drop wire press to enable the invention to is Hopedale, Mass,-

Serial No. 306,403.

grinding surface of the grinding member,

and a feeding device for presenting successive articles to the grinding member. The feeding device is'constructed and arranged so-that succeeding articles may be presented to different portions of the grinding surface of. the grinding member so that the latter may be worn down evenly over its entire surface, and the holding means by.

which the articles are maintained in contact with the grinding member, is of novel construction as will be hereinafter fully described.

The bur grinding machine illustrated in wires for the drawings is described in detail as follows: The grinding wheel 10' is mounted on the main driving shaft 12 supported in bearings 13 in the supporting frame 14. The main shaft 12 is driven from a source of power not shown, by the belt 15 which co-operates with a pulley 16 fast on the shaft 12. Provision is made for stopping and starting the rotation of the main shaft 12 by the loose pulley 17 and belt shifter 18. The frame 1 1 which supports the entire grinding machine is secured to the side of the frame of the drop wire press 20 by bolts 21. The latter is provided with the punch 22 and die 23 by means of which the drop wiresare stampedout as the metal blank 24 is fed thereunder.

As each drop wire is formed it is picked up and carried to the grinding wheel 10 by the endless fabric belt 25 which runs around the rolls 26, 27, and in which an even tension is maintained by the idler pulley 28. The endless belt 25 is driven by the roll 27 on the counter shaft 34, which derives its power from the main driving shaft 12 through the worm 30, gear 31, gear 32, and spiral gear 33 fast on the counter shaft 34, so that as long as the main shaft 12 is rotated, the endless belt 25 will operate to feed. the drop wires to the grinding wheel 10. The endless belt is enclosed within a guard or casing 35 supported by the frame 14 and which serves to prevent the drop wires from escaping fromor running off the belt. As the ,drop wires leave the endless belt 25, they strike against the guide shelf 37 and are guided thereby between feed rolls 38, 39, which are geared together and driven in a manner as will be described. The feed rolls 38, 39, are driven at a lower rate of speed than the grinding wheel 10 so that as each drop wire passes over the grinding wheel a perceptible drag is produced between the -under surface of the drop wire and the grinding wheel 10. This effectively grinds off the objectionable burs which have resulted from the stamping out operation in the press.

A plate 40 holds each drop wire in contact with the surface of the grinding wheel 10 as it-is fed across the same by the feed i rolls 38, 39, and is yieldingly and adjusta- ,piece 48 box-like bly mounted on the supporting frame 14 in a manner as will now be described.

The plate 40 is pivotally mounted upon ,a cross bar 41, by means of a pin 42 (see 3) which passes through small uprights 43 extended from the plate 40 and through the cross bar 41. A rod 44, threaded into the cross bar 41 and extended substantially perpendicularly therefrom. is slidabl'y supported in a casing 45. The casing 45 isprovided with an integral cross which is bolted at its side ends to a frame work 70, by bolts 71. The frame work 70 is provided with grooves which co-operate with upright standards 46, 47, of the supporting frame 14, so that the box-like frame, cross piece 48 and parts supported thereby are all slidably mounted upon the upright standards 46, 47, as guide posts, and are supported in any. desired position upon the standards 46. 47 by bolts 50-, 51, which thread into the cross piece 48 and'pass through holes in arms 52, 53. laterally extended from the topof the standards 46, 47, and by check nuts 54, 55, which limit the downward movement thereof. springs 56, 57,'between the cross piece 48, and the arms 52, 53, yieldingly hold the movable parts from upward movement. Thus it will be observed that as the surface of the grinding wheel wears down the plate 40 and associated parts may be bodily lowered to compensate for the wear of the grinding wheel by loosening the check nuts 54, 55.

The rod 44 which is adapted to slide within the casing 45 is supported by check nuts 58. 59,'hearing on the cap 60 threaded onto the end of the casing 45, and is yieldingly held from upward movement by the spring 62. which co-operates with a shoulder 61 on the rod 44 and with the cap member 60. in this manner the plate 40 is Coil 40 and to tilt it about its pivot pin 42 according to amount which the particular bolt is screwed down. This feature enables a very fine adjustment to be made so that the grinding wheel will operate to take off the bur only and will not damage the rest of the drop wire.

As each drop plate 40 and the grinding wheel 10 it is engaged by delivery rolls 75. 76. by which it is moved over the straightening bar 66 from which it is conveyed to separate machines where the eyes are ground and then the drop wires tumbled to round the edges.

The feed rolls 38, 39. and the delivery rolls 75, 76. are fast on shafts 80, 81. 82 and 83 respectively, which are journalled in bearings within the box-like frame work 70. and are geared together at one of their ends (see Figs. 2 and 5) by gears 77. 78 and 84. 85, respectively. The shafts 81 and 83 of the lower rolls 39 and 76 are journalled within the frame work in bearing boxes. which are shown as 88, 89, and which are yieldingly held upward by springs 90. 91. supported by the straps 92 secured to the bottom of the frame work 70. In this manner the lower of each pair of rolls is yieldingly held against the upper, so that drop wires of various thicknesses will be firmly engaged between both pairs of rolls.

The feed rolls 38, 39, and the delivery rolls 76, are driven from the main driving shaft 12 by a chain 95. which passes around and engages a sprocket gear 96 on the counter shaft 34. thence underneath and around a sprocket gear 97 on of the upper delivery roll (see Fig. 2) and around the idler sprockets 98. 99. and then back to the first sprocket 96 on the counter shaft 34. A second sprocket gear 100 on the shaft 82 transmits the rotations of this shaft by a second chain 101 to a sprocket gear 102 on the shaft of the upper feed roll. In this manner rotations of the counter shaft 34 are transmitted to the shaft 82 of the upper delivery roll. which in turn drives the shaft 80 of the upper feed roll. The lower feed roll 39 and delivery roll 76 are driven from the upper rolls 38 and 75, by the pairs of gears 77. 78 and 84, respectively.

The sizes of the various sprocket wheels and gears by which these rolls are driven wire passes between the the shaft 82' raaaeaa are such that they are rotated at a lower .rate of speed than the grinding wheel 10, so

that when a drop wire is being fed onto the grinding Wheel the difference in speed will. act as a drag which effectively operates to grind off the burs.

Continuous operation of the grinding machine subjects the surface of the grinding wheel to severe Wear so that in order to utilize the entire surface thereof, provision is made for automatically moving the endless belt 25 back and forth so that the drop wires will be fed to successive portions of the surface of the wheel and the wear on the grinding wheel will be uniform over its entire surface. To this end the roll 26 and guard or casing 35 are pivotally supported on a bracket 105 extended from the supporting frame 14 so that they may swivel back and forth about the pivot 106. The roll 27 is slidably mounted on the counter shaft 34 and 'splined thereon by the key 107, so that it is rotated by the counter shaft 84 but may be slidably moved back and forth thereon; The roll 27 is provided with annular grooves 108, 109, which support the free end of the guard or casing 35 so that it may be'moved back and forth with the roll 27. A third and deeper groove 110, in the roll 27 loosely receives a yoke 111 by means of which the roll 27, guard 35 and endless belt 25 may be slidably moved back and forth on the counter shaft 34, and for which purpose the rotations of the counter shaft 34 are transposed into reciprocatory movements of the yoke 111, and roll 27 engaged thereby, through the worm 112, gear 113, crank 114 carried thereby, and linkage 115, sothat as the main shaft 12, and grinding wheel 10 are rotated, the roll 27,

endless belt 25 and guard 35 are recipro- I cated continuously back and forth across the surface of the grinding wheel, so that as succeeding drop wires are carried by the belt 25 to the grinding wheel, they will be presented to difi'erent portions of the surface of the wheel 10.

After the machine has been operated for a considerable period of time the surface of the grinding wheel 10 may become worn to such an extent that it will be desirableto lower'jthe plate'40. By adjusting the check nuts 54, 55, on the bolts 50, 51, the entire frame worko may be lowered as a unit. It will be observed that the feed rolls 38, 39, delivery rolls 75, 76, together with the shafts 80, 81,82 and 83, upon which they are mounted, being all supported by the fl-frame work 70, may be lowered as a unit without being thrown out of adjustment in any way. This feature enables the I machine to be operated under the best conditions at all times, and further it is possible to utilize a single grinding wheel for an exceptionally long period of time, It

will be observed that the complete grinding machine automatically feeds, grinds and delivers the article, so that once its operation has been started, it requires a minimum amount of attention.

An important feature of the invention resides in the presser or holding means by which the moving metal articles are held against the grinding wheel.

While it is preferred to utilize a grinding wheel'as the grinding member it is not desired to limit the invention in this respect, as obviously any grinding member which will operate to grind the metal article when it is held against the same by the presser will be within the scope ofthe invention, and further while the invention has been described as embodied in a grinding machine for drop wires it is not desired to limit the invention in this respect.

We claim 1. A grinding machine having, in combi nation, a supporting frame, arotatable otally mounted on the supporting frame sothat the end thereof adjacent the grinding wheel may be moved laterally, and means for laterally reciprocating the said end of the belt conveyor.

2. A bur grinding machine for drop wires having, in combination, a supporting frame, a rotatable grinding wheel, means for rotating the grinding wheel, a device for holding succeeding drop wires against the grinding wheel comprising a cross piece adjustably secured to the supporting frame, 7

a rod slidably mounted in said cross piece,

and supported in yielding relation thereto,

a cross bar secured to the lower end of the rod, a plate pivoted to the cross bar, and adjusting screws threaded through the cross a bar and adapted to adjustably maintain the plate in any desired angular position.

, 3. A, grinding machine having, in combination. a grinding wheel, means for rotating the grinding wheel, a feeding mechanism constructed and arranged to move a plurality of articles in succession to a position to be operated upon by the grlndlng wheel, means for moving the feeding mechanism laterally to present successive articles todifi'erent portions of the grinding wheel, and means for holding each article thus presented in an operative position against the grinding wheelj 4. A. grinding machine having, in combination, a grinding member, a holding member for pressing an article against the grinding member, a feeding device constructed and arranged to move a plurality of articles in succession to,a position to be operated upon by the grinding member to present succeeding articles at different portions of the grinding member and means for laterally moving the feeding device.

5. A grinding machine having, in combination, a supporting frame provided with upright standards,- a rotatable grinding wheel mounted between said standards, a presser yieldingly mounted upon said standards and arranged to hold a metal article against the grinding wheel, said presser comprising a pivoted plate capable of angular adjustment with relation to the surface of the grinding wheel, and adjusting screws cooperating with the plate on each side of the pivot by which the angular position of the plate may be accurately adjusted. p

6. A grinding machine having, in combination, a supporting frame havin two upright standards, a rotatable grinding wheel mounted between said standards, a. framework adjustably mounted between said standards. a presser. feed rolls upon opposite sides of the presser and sprocket chain driving means for the feed rolls, said presser, feed rolls and sprockets, being mounted upon said framework whereby they may be adjusted as a unit to compensate for wear on the grinding wheel.

7. A grinding machine having, in combination, a supporting-frame having two up right standards, a rotatable grinding wheel mounted between the standards, a framework adjustably mounted between the standards and capable of movement lengthwise thereof,

feed rolls mounted upon the framework, and a presser yieldingly mounted upon the framework comprising a spring depressed rod,'a plate pivotally mounted upon the end of the rod and capable of angular adjustment with respect to the surface of the grinding wheel, and adjusting screws cooperating with the plate whereby the angular position of the plate with respect to the surface of the grinding wheel may be accurately determined.

' 8. A grinding machine having, in combination, a rotatable grinding wheel, means for rotating the same, a feeding belt arranged to deliver successive metal articles to the grinding wheel, and means for automatically reciprocating the belt to present the metal articles to difier'ent portions of the grinding wheel.

9. A grinding machine having, in combination. a rotatable grinding wheel, means for rotating the same including a driven shaft, and means for feeding successive dropwires to'the grinding wheel including a pivoted belt conveyor, and connections between ,the belt conveyor and driven shaft whereby the conveyor is constantly reciprocated to automatically present successive dropwires to different portions of the grinding wheel.

JONAS NORTHROP.

GEORGE E. KILBURN. PETER P. PESSOTTI. ERNEST L. TUCKER. 

